The international maritime industry, with more than 70,000 merchant vessels, is responsible for transporting more than 80% of the goods traded in world markets. Accordingly, it can be viewed as a foundation of the global economy. However, commercial shipping requires the use of ballast water, which is taken up when cargo is unloaded and discharged when cargo is loaded. The ballast water can contain marine life. Accordingly, when the water is discharged it can result in the introduction of aquatic invasive species to coastal waters where they can cause enormous ecological and economic damage.
The International Maritime Organization's (IMO) International Convention for the Control and Management of Ships' Ballast Water and Sediments, adopted in 2004 but not yet ratified or entered into force, includes a discharge standard to reduce the transport and delivery of potential Aquatic Nuisance Species. Concurrently in the United States, the U.S. Coast Guard (USCG) developed and finalized ballast water discharge standards (BWDSs) that limit concentrations of living organisms that can be released with ballast water and new regulations that require ship operators to meet those limits. The USCG discharge standard, which is the same as that of the IMO, will begin to apply to ships constructed on or after Dec. 1, 2013 and for ships constructed prior to that date in 2014 or 2016, depending on ballast water capacity. To address the IMO and U.S. discharge standards, technology developers and manufacturers around the world have designed and built a variety of on-board ballast water treatment systems (BWTS) to achieve the prescribed discharge limits. To date, several dozen BWTS have been tested by independent laboratories and have received type approval certifications from various international administrations in accordance with the IMO convention. These systems include treatment processes such as: de-oxygenation, filtration, ultraviolet radiation, ozonation, and various chemical treatments, including electro-catalytic chlorination, peracetic acid, hydrogen peroxide, perchloric acid, and chlorine dioxide.
At present, there are no commercially available technologies to verify the compliance of these BWTS consistently, and in real-time. Therefore, there is a need for a rapid in situ test/device that will determine whether ballast water discharge is compliant in accordance with the IMO and USCG standards.
Aspects of the present invention aim to address one or more drawbacks inherent in prior art methods and apparatus for detecting phytoplankton cells in ballast water.